DISTANCE FINDER ARDUINO

int trig=12;
int echo=11;
float duration,dist_cm,dist_in;
void setup() {
  // put your setup code here, to run once:
  pinMode(trig,OUTPUT);
  pinMode(echo,INPUT);
  Serial.begin(9600);
}

void loop() {
    // put your main code here, to run repeatedly:
    digitalWrite(trig,LOW);
    delayMicroseconds(2);
    digitalWrite(trig,HIGH);
    delayMicroseconds(10);
    digitalWrite(trig,LOW);
    
    duration=pulseIn(echo,HIGH);
    dist_cm=duration*0.0343/2.0;
    dist_in=duration*0.0315/2.0;
    Serial.print("Distance : ");
    Serial.print(dist_cm);
    Serial.print("cm/");
    Serial.print(dist_in);
    Serial.print("inches\n");
    delay(300);
}